Question: $420$ is what percent of $600$ ?
Having a percent of something means that you get that percent out of every $100$ We can set up a proportion to find out what percent of $600$ we need to take to get $420$ $ \dfrac{{\text{percent}}}{100} = \dfrac{{\text{part}}}{{\text{whole}}}$ Which things do we know, and what are we trying to find? We are trying to find the ${\text{percent}}$ . Is $600$ the ${\text{part}}$ or the ${\text{whole}}$ The $600$ is the ${\text{whole}}$ . This means the ${\text{part}}$ is $420$ $ \dfrac{{\text{percent}}}{100} = \dfrac{{420}}{{600}}$ If we divide the denominator of the fraction on the right by $6$ , it will be the same denominator of the fraction on the left. To keep things equal, let's also divide the numerator on the right by $6$ $ \dfrac{{\text{percent}}}{100 } = \dfrac{{420 \div 6}}{{600 \div 6}}$ $ \dfrac{{\text{percent}}}{100 } = \dfrac{{70}}{{100}}$ $ {\text{percent}} = {70}$ So $420$ is $70\%$ of $600$.